JP4997127B2 - Inspection method and program recording medium recording this inspection method - Google Patents

Description

  The present invention relates to an inspection method for inspecting an electrical property of an object to be inspected such as a semiconductor wafer using a probe card, and a program recording medium on which the inspection method is recorded, and more particularly to improve the reliability of the inspection. The present invention relates to a possible inspection method and a program recording medium on which the inspection method is recorded.

  The inspection apparatus includes a loader chamber and a prober chamber adjacent to each other. The loader chamber includes a placement unit for placing an object to be inspected (for example, a semiconductor wafer) in units of cassettes, a semiconductor wafer transfer mechanism for transferring semiconductor wafers one by one from the cassette, and a semiconductor in the middle of transferring the semiconductor wafers. And a sub-chuck that performs pre-alignment of the wafer. The prober chamber has a temperature-adjustable and movable main chuck on which the semiconductor wafer transferred by the wafer transfer mechanism of the loader chamber is placed, a probe card disposed above the main chuck, and a plurality of probe cards. An alignment mechanism that aligns the probe and a plurality of electrode pads of each of a plurality of devices formed on the semiconductor wafer on the main chuck, and performs alignment between the electrode pad of the semiconductor wafer and the probe via the alignment mechanism. After that, the semiconductor wafer is set to a predetermined temperature via the main chuck, and the electrical property inspection of the object to be inspected is performed at this set temperature.

  When an electrical characteristic inspection is performed on each device of a semiconductor wafer, an image of a device including a plurality of electrode pads formed on the semiconductor wafer is imaged and probed using an imaging means (for example, a CCD camera) of an alignment mechanism. The needle tips of a plurality of probes on the card are imaged, and the plurality of electrode pads and the plurality of probes are aligned based on the positional information of both. After that, the semiconductor wafer is raised by a predetermined dimension via the mounting table, and further overdriven to make electrical contact between the plurality of electrode pads and the plurality of probes, thereby inspecting the electrical characteristics of the device. However, with the high integration of devices, the electrode pads are rapidly miniaturized, the number of pads is increased, and the number of probes of the probe card is also increasing rapidly. For this reason, it has become difficult to detect a probe with a CCD camera during alignment.

  However, as the inspection is repeated, the needle tip position fluctuates due to deformation of a plurality of probes. When the plurality of probes are deformed and the needle tip position is gradually increased, the plurality of probes and the plurality of electrode pads may not be electrically connected even if the semiconductor wafer is overdriven. Therefore, in Patent Document 1, the overdrive amount is compared by detecting the needle trace formed on the actual pad with a camera, and when the needle tip position becomes high, the main chuck is always raised based on the comparison result. It describes a prober that gives a proper overdrive amount and can perform a stable inspection.

  Patent Document 2 obtains positional deviation information based on the contact state between the virtual pad (designed pad) and the probe, and not only virtually monitors the contact state between the actual pad and the probe in advance, but also An inspection apparatus that can correct an optimum contact state based on the result obtained in the contact state is described.

  In Patent Document 3, the position of the needle and the position of the electrode are detected, the image of the needle trace and the needle trace mark indicating the position of the needle trace are displayed on the display device, the positional deviation of the needle trace mark is calculated, and the operator A prober is disclosed that corrects the position of the needle mark on the image, calculates the position deviation of the needle mark, and corrects the movement amount calculation correction value of the semiconductor wafer based on the calculated deviation.

  Further, Patent Document 4 describes an inspection apparatus that obtains a positional deviation amount of a probe that comes into contact next based on a needle mark formed on an electrode pad. In this inspection apparatus, after a probe contacts an existing electrode pad on which a needle mark is formed, a post-contact image indicating a region including the electrode pad is obtained, and then the image is compared with an image before the contact. Describes a technique for acquiring the latest needle trace, correcting the positional deviation amount using the latest needle trace, and using the positional deviation amount for the next inspection.

JP-A-5-036765 JP-A-7-288270 JP 2006-339196 A JP 2006-278281

  However, all of the conventional techniques can correct the positional deviation between the plurality of electrode pads and the plurality of probes by determining the amount of positional deviation between the plurality of electrodes and the plurality of probes. There is no guarantee that the probes will contact each other within each electrode pad, and even if they come into contact with each other, repeated repeated contact with new needle tracks will damage the electrode pads and eventually cause the device to fail. There is a risk of damage.

  The present invention has been made to solve the above problems, and even when the electrode pad is miniaturized and thinned, the electrode pad of the object to be inspected can be obtained by using the needle trace formed on the electrode pad. It is an object of the present invention to provide an inspection method capable of performing a highly reliable inspection by repeatedly contacting a probe with high accuracy and a program recording medium recording the inspection method. Further, the present invention repeats the probe with high accuracy without damaging the electrode pad of the object to be inspected by using the needle trace formed on the electrode pad even when the electrode pad is miniaturized and thinned. It is an object of the present invention to provide an inspection method capable of performing a highly reliable inspection by bringing it into contact, and a program recording medium on which the inspection method is recorded.

  The inspection method according to claim 1 of the present invention electrically connects a plurality of electrode pads of an object to be inspected placed on a mounting table and a plurality of probes of a probe card arranged above the mounting table. The plurality of electrode pads and the plurality of electrode pads are prepared in preparation for the inspection by using the traces of the plurality of probes formed on each of the plurality of electrode pads by inspecting the electrical characteristics of the object to be inspected. A method of correcting a contact position with a plurality of probes, wherein the step of correcting the contact position between the plurality of electrode pads and the plurality of probes is prepared for each of the plurality of electrode pads in preparation for the inspection. A first step of imaging the plurality of electrode pads to detect the needle traces to obtain a first image, and using the first image, the center of each of the plurality of electrode pads and these On the electrode pad A second step of obtaining a positional deviation amount from the center of gravity of each of the needle traces, and contact positions of the plurality of probes used for the inspection with respect to the plurality of electrodes, the positions of the plurality of needle traces and the respective positions A third step of performing correction for alignment with the centers of the plurality of electrode pads by using a positional deviation amount; a plurality of probes used for the inspection after the correction in the third step; and the plurality of electrode pads; A fourth step of forming a new needle trace on each of the plurality of electrode pads by contacting the plurality of electrode pads, and a fifth step of obtaining a second image by imaging the plurality of electrode pads each formed with the new needle trace. And a sixth process for obtaining a contactable area of each of the plurality of probes in each of the electrode pads based on the size of the plurality of electrode pads and the center of gravity of a new needle mark on each of the electrode pads. When, is characterized in that it comprises a.

  The inspection method according to claim 2 of the present invention electrically connects the plurality of electrode pads of the object to be inspected placed on the mounting table and the plurality of probes of the probe card arranged above the mounting table. The plurality of electrode pads in preparation for the inspection using the probe marks of the plurality of probes formed on each of the plurality of electrode pads. And a step of correcting the contact positions of the plurality of probes, the step of correcting the contact positions of the plurality of electrode pads and the plurality of probes in preparation for the inspection, A first step of imaging the plurality of electrode pads to detect the needle traces formed on the first image to obtain a first image; and the center of each of the plurality of electrode pads using the first image. And these electrode pads A second step of obtaining a positional deviation amount with respect to the center of gravity of each of the needle traces on the needle, and a contact position of the plurality of probes used for the inspection with respect to the plurality of electrodes, and a position of the plurality of needle traces, respectively. A third step of performing correction to match the centers of the plurality of electrode pads using the positional deviation amount, and a plurality of probes and the plurality of electrode pads used for the inspection after correction in the third step A second step of forming a new needle trace on each of the plurality of electrode pads, and obtaining a second image by imaging the plurality of electrode pads each formed with the new needle trace. Step 5 and comparing the first image and the second image to extract a new needle trace image of each of the plurality of electrode pads, and extracting the plurality of extracted images and the second image Free space with no needle marks In comparison, when the plurality of extracted images are included in the respective empty areas, the step 6A for arranging the plurality of extracted images in the respective empty areas and obtaining the respective centers of gravity, and the contact positions of the plurality of probes And a seventh step of performing correction to match the centroids of the plurality of extracted images arranged in each of the empty areas.

  The inspection method according to claim 3 of the present invention electrically connects a plurality of electrode pads of an object to be inspected placed on a mounting table and a plurality of probes of a probe card arranged above the mounting table. The plurality of electrode pads in preparation for the inspection using the probe marks of the plurality of probes formed on each of the plurality of electrode pads. And a step of correcting the contact positions of the plurality of probes, the step of correcting the contact positions of the plurality of electrode pads and the plurality of probes in preparation for the inspection, A first step of imaging the plurality of electrode pads to detect the needle traces formed on the first image to obtain a first image; and the center of each of the plurality of electrode pads using the first image. And these electrode pads A second step of obtaining a positional deviation amount with respect to the center of gravity of each of the needle traces on the needle, and a contact position of the plurality of probes used for the inspection with respect to the plurality of electrodes, and a position of the plurality of needle traces, respectively. A third step of performing correction to match the centers of the plurality of electrode pads using the positional deviation amount, and a plurality of probes and the plurality of electrode pads used for the inspection after correction in the third step A second step of forming a new needle trace on each of the plurality of electrode pads, and obtaining a second image by imaging the plurality of electrode pads each formed with the new needle trace. And determining the contactable area of each of the plurality of probes in each of the electrode pads based on the step 5 and the size of the plurality of electrode pads and the center of gravity of a new needle mark on each of the electrode pads. Step 7A, determining whether each of the plurality of contactable areas is included in the plurality of electrode pads of the second image, and each of the plurality of contactable areas is the plurality of contact areas. When included in the electrode pad, an eighth step of extracting an image of a new needle trace in the plurality of electrode pads based on the first image and the second image, the plurality of extracted images, and the plurality of the plurality of extracted images Each of the contact areas of the electrode pads is compared with an empty area without a needle trace, and when the plurality of extracted images are included in the empty areas, the plurality of extracted images are arranged in the empty areas, respectively. And a ninth step of obtaining the center of gravity as the contact position of each of the plurality of probes.

  The inspection method according to claim 4 of the present invention electrically connects the plurality of electrode pads of the object to be inspected placed on the mounting table and the plurality of probes of the probe card arranged above the mounting table. The plurality of electrode pads in preparation for the inspection using the probe marks of the plurality of probes formed on each of the plurality of electrode pads. And a step of correcting the contact positions of the plurality of probes, the step of correcting the contact positions of the plurality of electrode pads and the plurality of probes in preparation for the inspection, A first step of imaging the plurality of electrode pads to detect the needle traces formed on the first image to obtain a first image; and the center of each of the plurality of electrode pads using the first image. And these electrode pads A second step of obtaining a positional deviation amount with respect to the center of gravity of each of the needle traces on the needle, and a contact position of the plurality of probes used for the inspection with respect to the plurality of electrodes, and a position of the plurality of needle traces, respectively. A third step of performing correction to match the centers of the plurality of electrode pads using the positional deviation amount, and a plurality of probes and the plurality of electrode pads used for the inspection after correction in the third step A second step of forming a new needle trace on each of the plurality of electrode pads, and obtaining a second image by imaging the plurality of electrode pads each formed with the new needle trace. And comparing the first image and the second image to extract the plurality of new needle trace images, respectively, and based on the centers of gravity of the plurality of extracted images and the centers of the electrode pads. The first Step 6B in which the plurality of probes come into contact with each other in the next inspection in the same procedure as in the third step, and the plurality of extracted images respectively arranged at the plurality of planned contact positions are already present. And 7B for correcting the estimated contact position by moving the estimated contact positions by the shortest distance to a position where the overlap of the needle traces with each other is minimized. Is.

  The inspection method according to claim 5 of the present invention electrically connects the plurality of electrode pads of the object to be inspected placed on the mounting table and the plurality of probes of the probe card arranged above the mounting table. The plurality of electrode pads in preparation for the inspection using the probe marks of the plurality of probes formed on each of the plurality of electrode pads. And a step of correcting the contact positions of the plurality of probes, the step of correcting the contact positions of the plurality of electrode pads and the plurality of probes in preparation for the inspection, A first step of imaging the plurality of electrode pads to detect the needle traces formed on the first image to obtain a first image; and the center of each of the plurality of electrode pads using the first image. And these electrode pads A second step of obtaining a positional deviation amount with respect to the center of gravity of each of the needle traces on the needle, and a contact position of the plurality of probes used for the inspection with respect to the plurality of electrodes, and a position of the plurality of needle traces, respectively. A third step of performing correction to match the centers of the plurality of electrode pads using the positional deviation amount, and a plurality of probes and the plurality of electrode pads used for the inspection after correction in the third step A second step of forming a new needle trace on each of the plurality of electrode pads, and obtaining a second image by imaging the plurality of electrode pads each formed with the new needle trace. And comparing the first image and the second image to extract the plurality of new needle trace images, respectively, and based on the centers of gravity of the plurality of extracted images and the centers of the electrode pads. The first In the same procedure as in the third step, the 6B step for obtaining the contact positions where the plurality of probes come into contact in the next inspection, and the existing plurality in the plurality of electrode pads in the second image, respectively. A Voronoi diagram is created based on the needle trace of each of the above, and the respective contact planned positions are corrected by moving the center of gravity of each of the extracted images arranged at the plurality of planned contact positions on the nearest Voronoi boundary line by the shortest distance. It is characterized by having the process of 7C.

  According to a sixth aspect of the present invention, in the inspection method according to any one of the first to fifth aspects, the new needle trace is an object to be inspected that is set to a predetermined temperature in advance. It is characterized by being formed using.

  According to a seventh aspect of the present invention, there is provided the inspection method according to any one of the first to sixth aspects, wherein the positional deviation amount obtained in the second step is the plurality of electrode pads. And the center of gravity of the needle mark formed on each of the plurality of electrodes, and is obtained by the least square method.

  The inspection method according to claim 8 of the present invention is the inspection method according to claim 1 or 3, wherein the range of the x-coordinate value of the contactable area obtained in the sixth step is the plurality of electrodes. With the center of the pad as the origin, a corrected x-coordinate value obtained by adding half the x-direction width of the new needle trace to the x-coordinate value of the negative edge of the electrode pad, and the maximum x-coordinate to this corrected x-coordinate value The larger one of the x coordinate values of the barycentric positions of the new needle traces having a value is obtained as the minimum x coordinate, and the x coordinate value of the plus side edge of the electrode pad and the minimum x coordinate at the edge are obtained. The smaller one of the x coordinate values of the barycentric positions of the new needle traces having coordinate values is obtained as the maximum x coordinate, and the y coordinate range of the contactable area is the range of the x coordinate values. It is obtained in the same way as It is intended to.

  According to a ninth aspect of the present invention, there is provided a program recording medium comprising: a plurality of electrode pads of a device to be inspected mounted on a mounting table and a probe card disposed above the mounting table by driving a computer; The probe is electrically contacted with each other, the electrical characteristics of the object to be inspected are inspected, and the needle traces of the plurality of probes formed on the electrode pads are used for the inspection. A program recording medium recording a program for executing an inspection method including a step of correcting contact positions between the plurality of electrode pads and the plurality of probes, and using the needle traces and the plurality of electrode pads The said program drives the said computer and correct | amends the contact position with a some probe, The inspection method of any one of Claims 1-8 is performed. It is an.

  According to the present invention, even when the electrode pad is miniaturized and thinned, the electrode pad of the object to be inspected and the probe are repeatedly contacted with high accuracy by using the needle trace formed on the electrode pad. It is an object of the present invention to provide an inspection method capable of performing a highly reliable inspection and a program recording medium recording the inspection method. Further, according to the present invention, even when the electrode pad is miniaturized and thinned, the probe and the high precision can be obtained without damaging the electrode pad of the object to be inspected by utilizing the needle trace formed on the electrode pad. It is an object of the present invention to provide an inspection method capable of performing a highly reliable inspection by repeatedly contacting the recording medium and a program recording medium recording the inspection method.

  Hereinafter, an embodiment of an inspection apparatus and an inspection method of the present invention will be described with reference to FIGS. In each figure, FIG. 1 is a block diagram showing the configuration of an inspection apparatus used for carrying out an embodiment of the method of the present invention, and FIG. 2 shows an embodiment of the inspection method of the present invention using the inspection apparatus shown in FIG. FIG. 3 is a flowchart showing further details of a part of the flowchart shown in FIG. 1, and FIGS. 4A and 4B show the amount of positional deviation based on the probe trace of the probe on the electrode pad of the device, respectively. 5A is a plan view showing correction, FIG. 5A is a diagram showing a state after correction, FIG. 5B is a diagram showing an ideal probe needle trace, and FIGS. 5A to 5C are second views, respectively. FIG. 6A is a plan view showing a process of extracting a new needle trace from the needle trace on the electrode pad of the first image using the existing needle trace of the electrode pad of the first image, and FIG. Explanatory drawing explaining other embodiment of the test | inspection method of invention, (a) of FIG. FIG. 8B is a plan view showing a probe contactable area on the electrode pad, and FIGS. 8A, 8B, and 8C are probe contactable areas on the electrode pad and the arrangement of probes allocated in the next inspection. FIG. 9A to FIG. 9C are plan views for explaining a method of optimally arranging the expected contact positions of the probes in the empty areas in the electrode pads, and FIG. FIGS. 11A and 11D are plan views for explaining a state where the probe contact position and the existing needle trace overlap each other, and FIGS. 11A to 11D are respectively the probe contact position and the existing contact position. FIG. 12A and FIG. 12B are plan views for explaining a method of correcting by moving the expected contact position of the probe to the optimum position, and FIG. 13 is a probe contact FIG. 14 is a plan view for specifically explaining a method for correcting the planned position by moving it to the optimum position. FIG. 14 is a diagram for correcting the planned contact position by moving to the optimum position when the planned contact position of the probe is applied to the passivation layer. FIG. 15A and FIG. 15B are plan views for explaining another method for correcting by moving the expected contact position of the probe to the optimum position.

First Embodiment First, an inspection apparatus provided with a program recording medium recording the inspection method of the present invention will be described. The inspection device 10, for example, as shown in FIG. 1, and rotatably mounting table 11 that moves to a built-in mounting to and temperature control mechanism of the semiconductor wafer W as an inspection target, above the mounting table 11 The probe card 12 arranged, the alignment mechanism 13 for aligning the plurality of probes 12A of the probe card 12 and the semiconductor wafer W on the mounting table 11, and the imaging means (for example, a CCD camera) constituting the alignment mechanism 13 13A, a display device having a display screen 14 for displaying an image picked up by the CCD camera 13A, and a control device 15 mainly composed of a computer for controlling these components, and under the control of the control device 15. The alignment mechanism 13 aligns the semiconductor wafer W on the mounting table 11 and the plurality of probes 12A of the probe card 12. After the door is constructed by electrical contact causes a plurality of probes 12A and the semiconductor wafer W so as inspecting electrical characteristics of the semiconductor wafer W.

  In addition, the inspection apparatus 10 includes an input unit 16 such as a display screen 14 and a keyboard as shown in FIG. 1, and various inspection conditions can be input by the input unit 16 in order to execute the inspection method of the present invention. Various programs and the like can be executed by operating menus and icons displayed on the display screen 14.

  As shown in FIG. 1, the mounting table 11 includes a drive mechanism 11A and a detector (eg, an encoder) 11B, and moves in the X, Y, Z, and θ directions via the drive mechanism 11A and moves via the encoder 11B. It is configured to detect the quantity. 11 A of drive mechanisms drive the XY table in which the mounting base 11 is arrange | positioned, for example, the horizontal drive mechanism (not shown) which mainly has a motor and a ball screw, the raising / lowering driving mechanism built in the mounting base 11, and mounting A θ drive mechanism that rotates the mounting table 11 in the θ direction. The encoder 11 </ b> B detects the movement distances in the X and Y directions of the XY table via the rotation speed of the motor, and transmits each detection signal to the control device 15. The control device 15 controls the drive mechanism 11A based on the signal from the encoder 11B, thereby controlling the amount of movement of the mounting table 11 in the X and Y directions.

  The alignment mechanism 13 includes the CCD camera 13A and the alignment bridge 13B as described above. As shown in FIG. 1, the CCD camera 13A is mounted on the alignment bridge 13B. The CCD camera 13A has a zoom function and images the semiconductor wafer W at a predetermined magnification.

  The CCD camera 13A advances from the back of the prober chamber to the probe center via the alignment bridge 13B, and is positioned between the probe card 12 and the mounting table 11, while the mounting table 11 moves in the X and Y directions. In addition, the semiconductor wafer W is imaged from above with a predetermined magnification, an imaging signal is transmitted to the control device 15, and an image of the semiconductor wafer is displayed on the display screen 14 via the control device 15.

  The control device 15 includes a central processing unit 15A, a program storage unit 15B that stores various programs including a program for executing the inspection method of the present invention, a storage unit 15C that stores various data, and a CCD. An image processing unit 15D that performs image processing on the imaging signal from the camera 13A, an image storage unit 15E that stores the image signal from the image processing unit 15D as image data, and a captured image on the display screen 14 based on the image signal. Display control unit 15F, and controls various components of the inspection apparatus 10 by transmitting and receiving signals between the central processing unit 15A, the program storage unit 15B, and the storage unit 15C.

An input unit 16 is connected to the central processing unit 15A, and various data signals input from the input unit 16 are processed by the central processing unit 15A and stored in the storage unit 15C. In the present embodiment, a program for executing the inspection method of the present invention is stored in the program storage unit 15B , and a captured image 14A, an operation panel 14B, and the like are displayed on the display screen 14. The operation panel 14B has a function of moving the mounting table 11 prior to alignment or registering image information such as position data of the probe card 12 before alignment as will be described later. That is, the mounting table 11 moves in the X and Y directions by pressing the horizontal movement operation key K1 of the operation panel 14B, and moves in the Z direction by pressing the vertical movement operation key K2 of the operation panel 14B. It is configured.

  An image storage unit 15E and a display control unit 15F are connected to the central processing unit 15A, and images captured by the CCD camera 13A are displayed on the display screen 14 via the central processing unit 15A and the display control unit 15F, respectively. . The image storage unit 15E can store past captured images, processed images, and the like in addition to the current captured images by the CCD camera 13A.

  Programs such as the inspection method of the present invention are stored in the program storage unit 15B via various recording media. Moreover, these programs can also be downloaded to various inspection apparatuses by a communication medium. In the present embodiment, the inspection method program stored in the program storage unit 15B is executed.

  Next, an embodiment of the inspection method of the present invention will be described with reference to FIGS. The inspection method of the present embodiment uses the needle trace inspection function attached to the inspection apparatus 10 and uses the existing needle trace formed on the electrode pad in the previous inspection (hereinafter referred to as “old needle trace”). After correcting the contact positions of the plurality of probes before the current examination, a plurality of probes are brought into contact with the plurality of electrode pads to form new needle traces (hereinafter referred to as “new needle traces”). It is characterized in that the next optimum contact position is obtained using the new needle trace. Therefore, the semiconductor wafer W used in the inspection method of this embodiment has already been subjected to at least one electrical characteristic inspection, and at least one probe trace is formed on each of the electrode pads of the plurality of devices. ing. In this inspection, the same probe card as that used in the previous inspection is used.

  In the inspection method of this embodiment, for example, the contact positions of the plurality of probes 12A are corrected according to the flowchart shown in FIG. Hereinafter, a case where the high-temperature inspection of the semiconductor wafer W is performed will be described.

  That is, as shown in FIG. 2, the device D having the electrode pad P (see FIG. 4) with the old needle trace F is imaged by the CCD camera 13A before the current contact (step S1). For this purpose, in the inspection apparatus 10, under the control of the control device 15, the semiconductor wafer W is mounted on the mounting table 11 in the prober chamber from the loader chamber by the wafer transfer mechanism, and the semiconductor wafer W is set to a predetermined level using the temperature adjustment mechanism. Heat to temperature (eg 150 ° C.). During this time, the alignment bridge 13B advances from the back surface of the prober chamber to the probe center and stops.

Thereafter, while the mounting table 11 moves in the X and Y directions, the CCD camera 13A of the alignment bridge 13B searches for a predetermined device D in the semiconductor wafer W at a low magnification, and the device D is directly below the CCD camera 13A. Then, the CCD camera 13A becomes high magnification and images a predetermined device D (step S1). The CCD camera 13A transmits the image pickup signal to the image processing unit 15D. Here, for example, the binarization processing of the picked-up image is performed based on the image pickup signal with reference to a predetermined threshold, and then the image is stored in the image storage unit 15E. Store as the first image. Further, the display control unit 15F of the control device 15 is activated to display the first image of the image storage unit 15E on the display screen 14 as shown in FIG.

  An enlarged version of the first image shown in FIG. 1 is the image shown in FIG. In FIG. 4A, the image of the device D is displayed as a binarized image, the electrode pad P is white, and the other part including the old needle trace F is displayed black. A broken line orthogonal to each other in each electrode pad P passes through a midpoint of each side of each electrode pad P, and an intersection of each broken line in the electrode pad P becomes an origin O of the xy coordinates of the electrode pad P. The cross mark of the old needle mark F indicates the center of gravity.

  FIG. 4B shows the needle trace Fi of an ideal probe card manufactured as designed. In the case of an ideal probe card, as shown in FIG. 4B, when a plurality of probes come into contact with the electrode pad P, the center of gravity of the needle trace Fi coincides with the origin O of the corresponding electrode pad P. However, the actual probe card 12 includes manufacturing errors and the like, and the tip positions of the probes 12A are slightly deviated from the origin of the electrode pad P in the x and y directions as described above.

Therefore, in this test to correct the contact position by using the needle traces F _i of the probe card of the old needle trace F and the ideal electrode pads P of the first image (step S2). To do this correction, it is necessary to obtain the positional deviation amount between the needle trace F _i of the old needle trace F and each of the ideal of the probes 12A. Therefore, the xy coordinates of the center of gravity of the old needle trace F are defined as (xi, yi) as shown in FIG. 4A, and the center of gravity of the ideal needle trace Fi is shown as shown in FIG. The xy coordinates are defined as (ui, vi). Then, the contact position of the probe card 12 is corrected by moving the semiconductor wafer W in the x and y directions by an error (x, y). The error Lt can be obtained by the following equation 1. However, it is assumed that there are n electrode pads P. 4A and 4B, the xy coordinate values of the center of gravity of the needle marks Fi and F attached to each electrode pad D are entered adjacent to each electrode pad P.
Lt = Σ ((xi− (x + ui)) ² + (yi− (y + vi)) ² ) Equation 1

Here, it is sufficient to obtain (x, y) at which the error Lt becomes the minimum value. Since the error Lt is a quadratic function of x and y, there is always a minimum value. Therefore, this minimum value can be obtained by partial differentiation of Lt with x and y. When Lt is partially differentiated with respect to x and y, the following equations 2A and 2B are obtained.
dLt / dx = 2nx + 2 (Σ (ui−xi)) = 0 Expression 2A
dLt / dy = 2ny + 2 (Σ (vi−yi)) = 0 Equation 2B

From the equations 2A and 2B, the following equations 3A and 3B are obtained. As is clear from these equations, (ui-xi) and (vi-yi) are deviation amounts between the old needle trace F and the ideal needle trace Fi, respectively, and therefore the correction amount is the actual number of probes 12A. It becomes the average value of the amount of deviation from the center of each electrode pad of the center of gravity of the old needle trace F. In order to bring the plurality of probes 12A into contact with the centers of the electrode pads P in this inspection, the semiconductor wafer W is corrected in the x direction and the y direction by the average amount of deviation of the center of gravity of the old needle trace F. It will be good. Therefore, by using this average value as the correction amount of the positional deviation, the center of gravity of the old needle trace F can be corrected in the current examination. However, the correction amount is (−x, −y) because the semiconductor wafer W is moved in the opposite direction to correct the positional deviation.
x = (Σ (ui−xi)) / n Equation 3A
y = (Σ (vi−yi)) / n Equation 3B

In step S2, after obtaining the correction amount of the contact position of the probe card 12, the mounting table 11 is moved by the correction amount in the x direction and the y direction, respectively, and the contact positions of the plurality of electrode pads P and the plurality of probes 12A are corrected. . Thereby, the alignment of the semiconductor wafer W and the probe card 12 is completed. Since this alignment is performed for all of the plurality of probes 12A, highly accurate alignment can be performed. After the alignment is completed, the mounting table 11 is raised to bring the semiconductor wafer W already heated to 150 ° C. into contact with the preheated probe card 12, and the mounting table 11 is further overdriven to form a plurality of electrode pads P of the device D. A plurality of probes 12A are brought into electrical contact to form a new needle trace (step S3). For example, an old needle trace F is formed on the electrode pad P having the first image as shown in FIG. 5A, and the corresponding probe 12A of the preheated probe card 12 is shown in FIG. ), A new needle trace, that is, a new needle trace Fn is formed.

  Subsequently, under the control of the control device 15, after the mounting table 11 is lowered to a predetermined position and the semiconductor wafer W is separated from the probe card 12, the alignment bridge 13B advances to the probe center, and the electrode pad P is moved by the CCD camera 13A. An image is taken (step S4). The CCD camera 13A transmits an image pickup signal to the image processing unit 15D, where the image processing is performed to obtain a binary image, and then this binary image is stored as a second image in the image storage unit 15E.

  Thereafter, under the control of the control device 15, a device D having a plurality of electrode pads P on which the new needle traces Fn are formed is displayed on the display screen 14 as a second image. Using the new needle traces Fn formed on the plurality of electrode pads P of the device D, the contact positions of the plurality of electrode pads P and the plurality of probes 12A are corrected in preparation for the next high temperature inspection. For this purpose, as in Step 2, the xy coordinate value of the center of gravity of the new needle mark Fn and the xy coordinate value of the center of the electrode pad P are applied to Equation 3A and Equation 3B, and the correction amount required in the next high temperature inspection Is obtained (step S5).

  In the present embodiment, not only the correction amount required in the next high temperature inspection is obtained, but also the contactable region S of the probe 12A on the electrode pad P is obtained according to the flowchart shown in FIG. Determines whether there is a free area that can contact the existing needle trace F without overlapping as much as possible. If there is such a free area, the correction amount of the probe 12A that forms the needle trace in the free area is obtained. .

  A method for obtaining the contactable region S of the probe 12A will be described with reference to FIG. FIG. 6A shows a state in which a vertical probe is used as the probe, and the tip of the vertical probe is displaced only in the x direction and there is no displacement in the y direction. If there is a positional shift in the y direction, it can be handled in the same way as in the x direction. Here, in order to simplify the method for obtaining the contactable region S, a case where a circular needle mark is formed on the electrode pad using a vertical needle will be described. However, in the cantilever type probe 12A, as shown in FIG. Although an oval needle trace is formed, the principle does not change at all in this case.

It is assumed that the needle trace F of each electrode pad P has a variation that is displaced from the center (ideal needle trace) of the electrode pad P only by Δx1, Δx2,. In this description, Δ is omitted. The center of gravity of the needle trace F having the smallest positional deviation in the x direction among the plurality of electrode pads P is x _min = min (x1, x2,... Xn), and the needle trace F having the largest positional deviation in the x direction is represented. The center of gravity is defined as x _max = max (x1, x2,... Xn).

The minimum value C _{min in the} x direction and the maximum value C _{max in} the x direction of the contactable region S of the vertical probe can be obtained by the following equations 4A and 4B. In these equations, w1 is the width dimension of the electrode pad P, and w2 is the diameter of the vertical probe. The following formulas 4A and 4B are formulas assuming that the width w1 of the electrode pad P and the diameter w2 of the vertical probe are all constant values. The contactable area S of the vertical probe obtained by the equations 4A and 4B is a rectangular area indicated by hatching in FIG. In formula 4A and formula 4B, w2 / 2 is added and subtracted in consideration of the radius of the vertical probe so that the vertical probe does not protrude from the passivation edge surrounding the electrode pad P.
C _min = max (−w1 / 2 + w2 / 2, −w1 / 2 + w2 / 2 + x _max )
... Formula 4A
_Cmax = min (w1 / 2-w2 / 2, w1 / 2-w2 / 2 + _xmin )
... Formula 4B

The above formulas 4A and 4B assume that the size of the electrode pad P and the size of the needle trace F of the probe 12A are the same. When the size of the electrode pad P and the size of the needle trace F of the probe 12A are different from each other, the following expressions 4Ci and 4Di are established as expressions corresponding to the above expressions 4A and 4B. In the following formulas 4Ci and 4Di, the width dimension of the i-th electrode pad P is defined as w1 _i , the diameter of the i-th probe 12A is defined as w2 _i, and the needle traces F of the electrode pad P and the probe 12A are inherently large. Some have different sizes, some have the same size. When the size of the electrode pad P and the size of the needle trace F of the probe 12A are not necessarily the same, the contactable region S in the i-th electrode pad P is obtained using the following equations 4Ci and 4Di, Using the formulas 4Ci and 4Di, the contactable area S for all the electrode pads P is obtained from the following formulas 4C and 4D. Next, the flowchart shown in FIG. 3 is executed by performing the same processing as in the case of obtaining the contactable region S by the above formulas 4A and 4B.
C _min (i) = max (−w1 _i / 2 + w2 _i / 2, −w1 _i / 2 + w2 _i / 2 + x _i )
... Formula 4Ci
_{C max (i) = min (} w1 i / 2-w2 i / 2, w1 i / 2-w2 i / 2 + x i)
... Formula 4Di
C _min = max (C _min (1), C _min (2), C _min (3), ... C _min (n))
... Formula 4C
C _max = min (C _max (1), C _max (2), C _max (3), ... C _max (n))
... Formula 4D

  That is, by substituting the xy coordinate value of the center of gravity of the new needle trace Fn into Equation 4A and Equation 4B, step S11 is executed as shown in FIG. 3, and the contactable regions of the plurality of probes 12A after preheating in the high temperature inspection are performed. S can be calculated. After obtaining the contactable region S, the central processing unit 15A determines whether or not the contactable region S is in the electrode pad P (step S12). If the contactable region S is in the electrode pad P, the plurality of probes 12A can reliably contact in all the electrode pads P and inspect the device D. However, if even a part of the contactable region S protrudes from the electrode pad P, the probe 12A that protrudes from the electrode pad P exists in the plurality of probes 12A, and a high-temperature inspection cannot be performed. Attention is given by issuing a warning by the action of the control device 15 (step S12A).

By the way, when the contactable region S includes the origin O of the electrode pad P as shown in FIG. 7A, the correction amount obtained based on the center of gravity of the old needle trace F under the control of the control device 15. As is, the semiconductor wafer W is moved to the contact position, so that the plurality of probes 12A can be brought into contact with the centers of the corresponding electrode pads P. However, if the above-described correction amount is used as it is when the contactable region S is off the center of the electrode pad P as shown in FIG. 7B, the electrode pad P that is out of the contactable region S is used. Therefore, any one of the plurality of probes 12A is out of the contactable region S, and the high temperature inspection cannot be performed. Therefore, in such a case, the xy coordinate value of the contactable region S closest to the center of the electrode pad P is added to the correction amount as an offset amount to move the semiconductor wafer W, thereby moving the plurality of probes 12A this time. Can be brought into contact with the centers of the corresponding electrode pads P. Furthermore, if the contactable area S is not formed or if the electrode pad is smaller than a predesignated size, the correction amount is not appropriate, and a warning is issued to call attention. This contactable area S can also be used in this high temperature inspection.

  When the contactable region S is formed in the electrode pad P, the current high temperature inspection can be performed, and the correction amount used for the next high temperature inspection can also be obtained. Here, this correction amount is defined as a second correction amount. In the case of obtaining the second correction amount in preparation for the next high temperature inspection, the second correction amount is used in the same manner as the correction amount based on the old needle trace F using the new needle trace Fn formed in the current high temperature inspection. The amount can be determined. That is, first, the centroids of the new needle traces Fn of the plurality of probes 12A are obtained, and then the second correction amount is calculated by fitting the centroid coordinates of these new needle traces Fn to Equations 3A and 3B.

  The new needle trace Fn is formed in the vicinity of the old needle trace F as shown in FIG. Since the new needle trace Fn shown in this figure does not overlap the old needle trace F, the center of gravity of the new needle trace Fn can be obtained in the same manner as the old needle trace F. However, if the new needle trace Fn partially overlaps the old needle trace F, the center of gravity of the new needle trace Fn cannot be determined. In this case, for example, the technique described in Japanese Patent Application Laid-Open No. 2006-27881 proposed by the present applicant can be applied. Here, a case where the new needle trace Fn does not overlap the old needle trace F will be described.

However, even in the case shown in FIG. 5B, the old needle trace F and the new needle trace Fn cannot be distinguished. Thus, in the present embodiment, the binarized first image including the old needle trace F imaged in step S2 and the binarized second image including both the old needle trace F and the new needle trace Fn. Only the new needle trace Fn is extracted using the image (step S13). That is, under the control of the control unit 15, first from the image storage unit 15E, the second images read to the central processing unit 15A, from which the second image when obtaining the difference between the first image, FIG. As shown by the broken line in 5 (c), the old needle trace F disappears and only the new needle trace Fn is extracted. The center of gravity of the new needle trace Fn can be obtained based on the image thus extracted (hereinafter referred to as “extracted image”). The new needle trace Fn is obtained for all of the plurality of probes 12A.

Thereafter, fitting contact region S and extract fraction image in the second image as shown in (a) of FIG. 8, the center of gravity of the extracted image image and in contactable region S of the electrode pad P Kyuhari Judgment is made as to whether or not the free space without the trace F and the new needle trace Fn is entered (step S14). In the case where the extracted image can be arranged in the vacant area within the contactable area S as indicated by the alternate long and short dash line in FIG. 8A, the extracted image is arranged as the expected contact position Fs of the probe 12A based on the extracted image ( Step S15), the center of gravity of the expected contact position Fs is obtained (Step S16). The center of gravity of the planned contact position Fs does not satisfy the above-mentioned condition, and the center of gravity of the planned contact position Fs protrudes from the contactable region S even if it is in the empty area of the electrode pad P as shown in FIG. Includes a probe 12A that causes a contact failure, and a high-temperature inspection cannot be performed. Therefore, a warning is issued to call attention (step S14A). Furthermore, as shown in FIG. 8C, the center of gravity of the planned contact position Fs is in the contactable area S, but when the planned contact position Fs cannot be arranged in the empty area, the existing old needle trace F and new The planned contact position Fs is arranged so that the overlap with the needle trace Fn is minimized. In this case, it is set so as to call attention that the planned contact position Fs cannot be arranged in the empty area, and the planned contact position Fs may be arranged so as to minimize the overlap based on the warning.

When the center of gravity of the expected contact position Fs is obtained as described above, these data are stored in the image storage unit 15E and stored in the image storage unit 15E. These data are used when the next high temperature inspection is performed. Further, when the next high temperature inspection is performed by another inspection apparatus, these data are transplanted to another inspection apparatus using a communication medium or a magnetic recording medium.

  When the above operation is completed, the inspection apparatus 10 performs index feeding of the semiconductor wafer W by the mounting table 11 under the control of the control apparatus 15 to perform the current high-temperature inspection. When the high temperature inspection of one semiconductor wafer W is completed, the subsequent semiconductor wafer W is mounted on the mounting table 11. Since this semiconductor wafer W is the same as the previous semiconductor wafer W, alignment is omitted, and the semiconductor wafer W is index-fed to perform a high temperature inspection.

  As described above, according to the present embodiment, in this high temperature inspection, the plurality of electrode pads P of the semiconductor wafer W placed on the mounting table 11 and the probe card 12 arranged above the mounting table 11 The plurality of probes 12A are brought into electrical contact, the electrical characteristics of the plurality of devices D in the semiconductor wafer W are inspected, and the old needle traces F of the plurality of probes 12A formed on each of the plurality of electrode pads P are obtained. And using the step of correcting the contact positions of the plurality of electrode pads P and the plurality of probes 12A in preparation for the inspection, and the step of correcting the contact positions of the plurality of electrode pads P and the plurality of probes 12A. Imaging a plurality of electrode pads P to detect an old needle trace F formed on each of the electrode pads P to obtain a first image, and using the first image, the plurality of electrode pads P The A plurality of contact positions of the plurality of probes P used in the current inspection with respect to the plurality of electrode pads P are obtained. A step of correcting the center of the plurality of electrode pads P using the center of gravity of the old needle trace F and the amount of displacement, and a plurality of probes 12A used for the current inspection after the correction in this step, A step of bringing the plurality of electrode pads P into contact with each other to form the new needle traces Fn; a step of imaging the plurality of electrode pads P each having the new needle traces Fn formed thereon; and obtaining a second image; Obtaining each contactable area S of each of the plurality of probes 12A in each electrode pad P based on the size of the electrode pad P and the center of gravity of the new needle trace Fn in each electrode pad P. Therefore, even when the electrode pad P is miniaturized, the old needle trace F is reliably detected by the CCD camera 13A, and a plurality of probes 12 in the current inspection are aligned to form a new needle trace Fn. Furthermore, the contactable area S of the plurality of probes 12A is obtained using the new needle trace Fn, and the plurality of electrode pads P and the corresponding plurality of probes 12A are brought into electrical contact with each other reliably to ensure high reliability at high temperature. Can be performed reliably.

In addition, according to the present embodiment, the step of correcting the contact positions of the plurality of electrode pads P and the plurality of probes 12A in preparation for the inspection detects the old needle traces F formed on each of the plurality of electrode pads P. In order to obtain a first image by imaging a plurality of electrode pads P, and using the first image, the center of each of the plurality of electrode pads P and each of the old needle traces F in these electrode pads P The step of obtaining the positional deviation amount with respect to the center of gravity and the contact positions of the plurality of probes P used for the current inspection with respect to the plurality of electrode pads P are determined using the center of gravity of the plurality of old needle traces F and the respective positional deviation amounts. A process of correcting each of the centers of the plurality of electrode pads P, and after correcting in this process, the plurality of probes 12A used for the current inspection and the plurality of electrode pads P are brought into contact with each other to form new needle traces Fn. Form A step of imaging a plurality of electrode pads P each having a new needle trace Fn to obtain a second image; and comparing the first image and the second image to compare each of the plurality of electrode pads P extracting an image of Shinhariato Fn, compares with these and a plurality of extraction image image needle mark-free space area of the second image, each free space when multiple extraction picture image included in each of the free space a step of determining the respective centroids are arranged as a contact scheduled position Fs of the probes 12A based on a plurality of extracted images within, each of the probes 12A contact positions of the plurality of contact predetermined position Fs disposed in each free area And a process of performing correction to match the center of gravity. Therefore, even when the electrode pad P is miniaturized, the old needle trace F formed on the electrode pad P can be used for the next high temperature inspection. Probe 12A Contacting the free space of each of the electrode pads P, to prevent damage to the respective electrode pads P, it is possible to perform a highly reliable high-temperature inspection.

Furthermore, according to the present embodiment, when each of the plurality of contactable areas S is included in the plurality of electrode pads P, new needle traces in the plurality of electrode pads P extracted from the first image and the second image are displayed. step a, a plurality of extract fraction images and a plurality of electrode pads P respectively contactable in the region S and the needle trace without a free area compared respectively, a plurality of extraction picture images each free space for obtaining the extract fraction images Are arranged as the expected contact position Fs of the probe 12A based on a plurality of extracted images in each empty area and the respective centers of gravity are obtained, and the contact positions of each of the plurality of probes 12A and the plurality arranged in the empty area of reliable contact because it and a step of correcting to match the center of gravity of the contact predetermined position Fs, the free space of each of the electrode pads P and the probes 12A in the next high-temperature inspection of , To prevent damage to the respective electrode pads P, it is possible to perform a highly reliable high-temperature inspection.

Second Embodiment In the present embodiment, an inspection method in which the probe 12A is efficiently brought into contact in an empty area formed between a plurality of needle traces on the electrode pad P will be described with reference to FIGS. . The empty area refers to an area in the electrode pad P where the probe 12A can contact without overlapping with existing needle traces. When there are a plurality of existing needle traces and the probe 12A cannot contact without overlapping with the existing needle traces, the optimum position of the planned contact position that minimizes the overlap with the existing needle traces is searched for. By minimizing the overlap with the existing needle traces, it is possible to prevent damage to the electrode pad, and thus damage to the device. The expected contact position can be obtained by the same procedure as in the first embodiment. In FIGS. 9 to 14, a circumscribed rectangle of the needle trace is shown instead of the needle trace.

  There are two ways to find a free area. The first method is a method of moving the probe 12A to a position closest to the planned contact position at a position where the overlap with the existing needle trace in the electrode pad is minimized. The second method maintains the positional relationship with the existing needle traces around the planned contact position, and is closest to the planned contact position at a position where the overlap with the existing needle trace in the electrode pad P is minimized. This is a method of moving the probe 12A to a position.

  For example, as shown in FIG. 9A, two existing old needle traces (indicated by a circumscribed rectangle of the needle trace) F1 and F2 and one old needle trace F2 are used in the electrode pad P. A new needle trace (indicated by a circumscribed rectangle of the needle trace) Fn obtained by correcting the contact position of the probe 12A this time is formed, and the center of gravity of the new needle trace Fn and the center of the electrode pad P are formed. The position of the new needle trace Fn is corrected in the same manner as in the first embodiment using the positional deviation amount, and the contact position (indicated by the circumscribed rectangle of the needle trace) Fs of the probe 12A in the next inspection is obtained. It is a thing. The planned contact position Fs partially overlaps the old needle trace F2 and the new needle trace Fn as shown in FIG. Therefore, in the present embodiment, the position where the overlap between the old needle trace F2 and the new needle trace Fn at the planned contact position Fs is corrected as the optimum position Fc of the planned contact position Fs.

  In the first method, the optimum position (position that does not overlap with the existing needle traces F1, F2, and Fn) Fc of the entire electrode pad P does not overlap with any needle trace as shown in FIG. 9B. And the position is obtained as the expected contact position Fa of the next inspection. In this case, the overlapping portion becomes zero. However, this method has a problem that the empty area is reduced at a stretch when the next inspection is performed.

  In the second method, while maintaining the positional relationship between the existing old needle trace F2 and the new needle trace Fn, a free area is obtained and the expected contact position Fs is corrected to the optimum position Fc. The overlap between the expected contact position Fs and the existing needle traces F2 and Fn is minimized to prevent the electrode pad P from being damaged. Even when an empty area is obtained, the optimum position Fc is preferably as close to the planned contact position Fs as possible. This is because, after the probe 12A has contacted the optimum position Fc, the contact position is returned to the expected contact position Fs and may come into contact with another position. Therefore, the second method will be further described below with reference to FIGS.

  In order to obtain the optimum position Fc within the empty area from the estimated contact position Fs, the estimated contact position Fs corrected based on the positional deviation amount between the center of gravity of the existing new needle trace Fn and the center of the electrode pad P is, for example, shown in FIG. As shown in (a) and (b), it is assumed that it partially overlaps with the existing new needle trace Fn.

  In this method, the overlap between the planned contact position Fs and the new needle trace Fn is examined in FIGS. 10A and 10B, and for example, which side of the planned contact position Fs overlaps with the new needle trace Fn is specified. Of the sides where the planned contact position Fs overlaps, the side with a large overlap is defined as the target segment. In FIG. 10A, since the intercept on the right side indicated by the bold line of the planned contact position Fs is larger than the intercept on the upper side, the intercept on the right side indicated by the bold line is the target segment. In FIG. 6B, the upper side segment indicated by the bold line of the planned contact position Fs is larger than the right side segment, so the upper side segment indicated by the thick line is the target segment. In addition to the target sections shown in FIGS. 10A and 10B, there are types shown in FIGS. 11A to 11D, for example.

  In order to minimize or eliminate the overlap while maintaining the positional relationship between the planned contact position Fs and the new needle trace Fn, the planned contact position Fs is moved in the vertical direction of the target section with reference to the overlapping portion of the other side. Thus, the overlap of the expected contact position Fs can be minimized or zero. In the case shown in FIG. 10 (a), if the planned contact position Fs is moved to the left by the overlap of the other side as shown in FIG. 12 (a) to FIG. become. In the case shown in FIG. 10B, the overlap is zero when the planned contact position Fs is moved downward by the overlap of the other side. The type shown in FIG. 11A includes the type shown in FIG. 10 and can be corrected to the optimum position based on the target segment. In addition, in the case of the types shown in FIGS. 11B and 11C, since one target section is included, the expected contact position Fs can be corrected to the optimum position. However, in the case of the type shown in (d) of FIG. 11, the optimum position cannot be set because there are a plurality of target sections. Accordingly, in the case of the type shown in FIG. 11D, correction to the optimum position is not performed.

Further, as shown in FIGS. 9A and 13, when the planned contact position Fs overlaps both the old needle trace F2 and the new needle trace Fn, the planned contact position Fs so that the overlap is zero. Can not be moved. In this case, the expected contact position Fs is moved so that the target segment moves in the vertical direction so that the left and right overlaps are equal. Thus, the damage in both needle traces can be reduced by dividing the overlapping portion equally on the left and right. In FIG. 13, the length of the target section of the planned contact position Fs and the new needle trace Fn is ay, the length of the other overlapping side is ax, and the length of the target section of the planned contact position Fs and the old needle trace F2 is by. If the length of the other overlapping side is bx, the movement amount x in the x direction can be obtained by the following equation.
SL (overlapping area with old needle trace after movement) = (bx−x) × by
SR (overlap area with new needle trace after movement) = (ax + x) × ay
Here, x is obtained from the relationship SL = SR.
(Bx−x) × by = (ax + x) × ay
Therefore, the movement amount x = (bxby−axay) / (ay + by)
It becomes.

  After obtaining the amount of movement in the x direction in this way, the amount of movement in the y direction is obtained in the same manner as the amount of movement in the x direction, and the expected contact position Fs is optimized.

  Instead of a movement amount that makes the overlap amount equal on the left and right, a movement amount that minimizes the sum of the left and right overlap areas and a movement amount that makes the overlap width (ax, bx in FIG. 13) equal may be obtained.

  In order to perform the optimal movement in the x direction as described above, a directed graph (hereinafter referred to as an “adjacency relationship graph”) having an existing needle trace and a planned contact position as a node, which represents an adjacent relationship of existing values in advance. Is created, an existing needle trace related to the expected contact position Fs is identified from the adjacent relationship graph, and an evaluation amount such as an overlap width with the existing needle trace is obtained.

  When the planned contact position Fs overlaps both the new needle trace Fn and the passivation edge as shown in FIG. 14, if the side that is a certain distance from the passivation edge is considered in the same way as the side of the existing needle trace circumscribed rectangle, The expected contact position Fs can be moved to the optimum position between the new needle trace Fn and the passivation by the method described above. In addition, when the condition of separating from the passivation edge by a certain distance or more must be satisfied, a movement amount that minimizes the overlap with the existing new needle trace Fn is obtained after satisfying the condition. In FIG. 14, the outer side of the broken line is a passivation layer.

  In the present embodiment, the method of obtaining the movement amount using the circumscribed quadrangle of the needle trace when the planned contact position Fs is moved to the optimum position Fc has been described. However, a binarized image indicating an actual needle trace area is used. The overlapping portion may be calculated by bitmap calculation.

  As described above, according to the present embodiment, a plurality of contact plans are obtained as steps after the respective contact positions Fs at which the plurality of probes 12A contact in the next inspection are obtained in the same procedure as in the first embodiment. When the extracted images (circumscribed square) Fn of the plurality of needle traces respectively arranged at the position Fs overlap with the existing needle trace (circumscribed square) F1, the target section at the position where the overlap is minimum, that is, the target section at the planned contact position Fs is selected. Since there is a step of correcting the estimated contact position Fs by moving each estimated contact position Fs in the vertical direction by the shortest distance, the estimated contact position Fs is efficiently arranged in the empty area and the existing needle traces are arranged. In addition to being able to suppress damage to F1 and Fn and thus suppressing damage to the device, it is possible to achieve the same effects as in the first embodiment.

Third Embodiment In this embodiment, a Voronoi diagram is created for the center of gravity of an existing needle trace as shown in FIG. In this embodiment, the needle trace is represented by a circumscribed rectangle of the needle trace as in the second embodiment. A Voronoi diagram is a diagram in which a plurality of points (mother points) placed at arbitrary positions in a certain metric space are divided into regions according to which mother point the points in the same metric space are close to. say. The boundary line of the region becomes a part of the bisector of the generating point of each region. As shown in FIG. 15 (a), the Voronoi boundary L will be the farthest from the existing needle traces F1, F2, Fn of the center of gravity. As shown in FIG. 15B , the position closest to the Voronoi boundary line L from the center of gravity of the planned contact position Fs obtained based on the new needle trace Fn is the optimized optimum position Fc.

  According to the present embodiment, instead of efficiently arranging the planned contact position Fs of the probe 12 in the empty area using the circumscribed rectangle of the needle traces F1 and Fs in the second embodiment, the existing needle traces F1, F2, The expected contact position Fs can be efficiently arranged using the Voronoi diagram of Fn, and the same effect as the second embodiment can be expected.

  In addition, although the said embodiment demonstrated the high temperature test | inspection of to-be-inspected object, it is applicable not only to a high temperature test | inspection but to various other test | inspections similarly. The present invention is not limited to the above-described embodiment, and each component can be changed as appropriate.

  INDUSTRIAL APPLICABILITY The present invention can be suitably used for an inspection apparatus that inspects electrical characteristics of an object to be inspected such as a semiconductor wafer.

It is a block diagram which shows the structure of the test | inspection apparatus used in order to implement one Embodiment of the method of this invention. It is a flowchart which shows one Embodiment of the test | inspection method of this invention using the test | inspection apparatus shown in FIG. It is a flowchart which shows a part of flowchart shown in FIG. 1 further in detail. (A), (b) is a top view which shows correction | amendment of a positional offset amount based on the probe trace of the probe in the electrode pad of a device, respectively, (a) is a figure which shows an old needle trace , (b) is ideal It is a figure which shows the needle trace of this probe. (A)-(c) is a top view which shows the process of extracting a new needle trace from the needle trace on the electrode pad of a 2nd image, respectively using the existing needle trace of the electrode pad of a 1st image. . (A), (b) is explanatory drawing explaining other embodiment of the test | inspection method of this invention, respectively. (A), (b) is a top view which shows the contactable area | region of the probe in an electrode pad, respectively. (A), (b), (c) is a figure which shows the relationship between the probe contactable area | region in an electrode pad, and the arrangement | positioning area | region of the probe allocated by the next test | inspection, respectively. (A)-(c) is a top view for demonstrating the method of optimally arrange | positioning the contact position of a probe in the empty area | region in an electrode pad, respectively. (A), (b) is a top view for demonstrating the state where the contact position of a probe and the existing needle trace overlap, respectively. (A)-(d) is a top view for demonstrating the state where the contact position of a probe and the existing needle trace overlap, respectively. (A), (b) is a top view for demonstrating the method to correct | amend by moving the contact position of a probe to the optimal position, respectively. It is a top view for demonstrating concretely the method of moving and correcting the contact position of a probe to the optimal position. It is a top view for demonstrating the method of moving to the optimal position when the estimated contact position of a probe is applied to the passivation layer, and correct | amending an estimated contact position. (A), (b) is a top view for demonstrating the other method which correct | amends by moving the contact position of a probe to the optimal position, respectively.

Explanation of symbols

10 Inspection device (Inspection device)
11 Mounting table (mounting table)
12 probe card 12A probe 13A CCD camera 15 control device (computer)
15A Central processing unit D Device F Old needle trace (needle trace)
Fn New needle trace Fs Extract image P Electrode pad W Semiconductor wafer (inspected object)

Claims (9)

A plurality of electrode pads of the object to be inspected placed on the mounting table and a plurality of probes of the probe card arranged above the mounting table are in electrical contact to inspect the electrical characteristics of the object to be inspected And a step of correcting the contact positions of the plurality of electrode pads and the plurality of probes in preparation for the inspection using the needle traces of the plurality of probes formed on each of the plurality of electrode pads. A method,
The step of correcting the contact positions of the plurality of electrode pads and the plurality of probes in preparation for the inspection,
A first step of obtaining a first image by imaging the plurality of electrode pads in order to detect the needle marks formed on each of the plurality of electrode pads;
A second step of obtaining a positional shift amount between the center of each of the plurality of electrode pads and the center of gravity of each of the needle marks on these electrode pads using the first image;
Third correction for adjusting the contact positions of the plurality of probes used in the inspection to the plurality of electrodes to the centers of the plurality of electrode pads using the positions of the plurality of needle marks and the respective positional deviation amounts. And the process of
A fourth step of forming a new needle trace on each of the plurality of electrode pads by bringing the plurality of probes used for the inspection into contact with the plurality of electrode pads after correction in the third step;
A fifth step of obtaining a second image by imaging a plurality of electrode pads each having the new needle trace formed thereon;
A sixth step of determining within each electrode pad the accessible area of each of the plurality of probes based on the size of the plurality of electrode pads and the center of gravity of a new needle mark on each electrode pad. Inspection method characterized by A plurality of electrode pads of the object to be inspected placed on the mounting table and a plurality of probes of the probe card arranged above the mounting table are in electrical contact to inspect the electrical characteristics of the object to be inspected And a step of correcting the contact positions of the plurality of electrode pads and the plurality of probes in preparation for the inspection using the needle traces of the plurality of probes formed on each of the plurality of electrode pads. A method,
The step of correcting the contact positions of the plurality of electrode pads and the plurality of probes in preparation for the inspection,
A first step of obtaining a first image by imaging the plurality of electrode pads in order to detect the needle marks formed on each of the plurality of electrode pads;
A second step of obtaining a positional shift amount between the center of each of the plurality of electrode pads and the center of gravity of each of the needle marks on these electrode pads using the first image;
Third correction for adjusting the contact positions of the plurality of probes used in the inspection to the plurality of electrodes to the centers of the plurality of electrode pads using the positions of the plurality of needle marks and the respective positional deviation amounts. And the process of
A fourth step of forming a new needle trace on each of the plurality of electrode pads by bringing the plurality of probes used for the inspection into contact with the plurality of electrode pads after correction in the third step;
A fifth step of obtaining a second image by imaging a plurality of electrode pads each having the new needle trace formed thereon;
The first image and the second image are compared to extract a new needle trace image of each of the plurality of electrode pads, and the plurality of extracted images and the second image are free of needle traces. Step 6A for comparing the area, and when the plurality of extracted images are included in each empty area, the plurality of extracted images are arranged in each empty area and the respective centroids are obtained.
And a seventh step of correcting the contact position of each of the plurality of probes to match the center of gravity of the plurality of extracted images arranged in each of the empty regions. A plurality of electrode pads of the object to be inspected placed on the mounting table and a plurality of probes of the probe card arranged above the mounting table are in electrical contact to inspect the electrical characteristics of the object to be inspected And a step of correcting the contact positions of the plurality of electrode pads and the plurality of probes in preparation for the inspection using the needle traces of the plurality of probes formed on each of the plurality of electrode pads. A method,
The step of correcting the contact positions of the plurality of electrode pads and the plurality of probes in preparation for the inspection,
A first step of obtaining a first image by imaging the plurality of electrode pads in order to detect the needle marks formed on each of the plurality of electrode pads;
A second step of obtaining a positional shift amount between the center of each of the plurality of electrode pads and the center of gravity of each of the needle marks on these electrode pads using the first image;
Third correction for adjusting the contact positions of the plurality of probes used in the inspection to the plurality of electrodes to the centers of the plurality of electrode pads using the positions of the plurality of needle marks and the respective positional deviation amounts. And the process of
A fourth step of forming a new needle trace on each of the plurality of electrode pads by bringing the plurality of probes used for the inspection into contact with the plurality of electrode pads after correction in the third step;
A fifth step of obtaining a second image by imaging a plurality of electrode pads each having the new needle trace formed thereon;
A sixth step of determining within each electrode pad the accessible area of each of the plurality of probes based on the size of the plurality of electrode pads and the center of gravity of a new needle mark on each electrode pad;
A step of 7A for determining whether or not each of the plurality of contactable regions is included in each of the plurality of electrode pads of the second image;
An eighth step of extracting an image of a new needle trace in the plurality of electrode pads based on the first image and the second image when each of the plurality of contactable areas is included in the plurality of electrode pads; When,
Each of the plurality of extracted images is compared with an empty area without a needle trace in each of the contactable areas of the plurality of electrode pads, and when the plurality of extracted images are included in each of the empty areas, And a ninth step of arranging the plurality of extracted images and obtaining respective centroids as contact positions of the plurality of probes. A plurality of electrode pads of the object to be inspected placed on the mounting table and a plurality of probes of the probe card arranged above the mounting table are in electrical contact to inspect the electrical characteristics of the object to be inspected And a step of correcting the contact positions of the plurality of electrode pads and the plurality of probes in preparation for the inspection using the needle traces of the plurality of probes formed on each of the plurality of electrode pads. A method,
The step of correcting the contact positions of the plurality of electrode pads and the plurality of probes in preparation for the inspection,
A first step of obtaining a first image by imaging the plurality of electrode pads in order to detect the needle marks formed on each of the plurality of electrode pads;
A second step of obtaining a positional shift amount between the center of each of the plurality of electrode pads and the center of gravity of each of the needle marks on these electrode pads using the first image;
Third correction for adjusting the contact positions of the plurality of probes used in the inspection to the plurality of electrodes to the centers of the plurality of electrode pads using the positions of the plurality of needle marks and the respective positional deviation amounts. And the process of
A fourth step of forming a new needle trace on each of the plurality of electrode pads by bringing the plurality of probes used for the inspection into contact with the plurality of electrode pads after correction in the third step;
A fifth step of obtaining a second image by imaging a plurality of electrode pads each having the new needle trace formed thereon;
The first image and the second image are compared to extract a plurality of new needle trace images, respectively, and the first to first based on the centroids of the plurality of extracted images and the centers of the respective electrode pads. A step 6B for obtaining respective planned contact positions at which the plurality of probes contact in the next inspection in the same procedure as the third step;
When the plurality of extracted images respectively arranged at the plurality of planned contact positions overlap with existing needle traces, the respective planned contact positions are moved by the shortest distance to a position where the overlap is minimized. And a seventh step B for correcting the above. A plurality of electrode pads of the object to be inspected placed on the mounting table and a plurality of probes of the probe card arranged above the mounting table are in electrical contact to inspect the electrical characteristics of the object to be inspected And a step of correcting the contact positions of the plurality of electrode pads and the plurality of probes in preparation for the inspection using the needle traces of the plurality of probes formed on each of the plurality of electrode pads. A method,
The step of correcting the contact positions of the plurality of electrode pads and the plurality of probes in preparation for the inspection,
A first step of obtaining a first image by imaging the plurality of electrode pads in order to detect the needle marks formed on each of the plurality of electrode pads;
A second step of obtaining a positional shift amount between the center of each of the plurality of electrode pads and the center of gravity of each of the needle marks on these electrode pads using the first image;
Third correction for adjusting the contact positions of the plurality of probes used in the inspection to the plurality of electrodes to the centers of the plurality of electrode pads using the positions of the plurality of needle marks and the respective positional deviation amounts. And the process of
A fourth step of forming a new needle trace on each of the plurality of electrode pads by bringing the plurality of probes used for the inspection into contact with the plurality of electrode pads after correction in the third step;
A fifth step of obtaining a second image by imaging a plurality of electrode pads each having the new needle trace formed thereon;
The first image and the second image are compared to extract a plurality of new needle trace images, respectively, and the first to first based on the centroids of the plurality of extracted images and the centers of the respective electrode pads. A step 6B for obtaining respective planned contact positions at which the plurality of probes contact in the next inspection in the same procedure as the third step;
A Voronoi diagram is created based on the plurality of existing needle traces in each of the plurality of electrode pads of the second image, and the center of gravity of each of the extracted images arranged at the plurality of planned contact positions is determined as the nearest Voronoi. An inspection method comprising: a step 7C for correcting each of the planned contact positions by moving it to the boundary line with the shortest distance.   The inspection method according to any one of claims 1 to 5, wherein the new needle trace is formed using an object to be inspected that is set in advance to a predetermined temperature.   The positional deviation amount obtained in the second step is obtained by a least square method using the centers of the plurality of electrode pads and the centers of gravity of the needle marks formed on each of the plurality of electrodes. The inspection method according to any one of claims 1 to 6.   The range of the x-coordinate value of the contactable area obtained in the sixth step is set to the x-coordinate value of the negative edge of the electrode pad as the x-coordinate value of the new needle trace with the center of the plurality of electrode pads as the origin. The larger of the corrected x-coordinate value obtained by adding half the width and the x-coordinate value of the barycentric position of the new needle trace having the maximum x-coordinate value to the corrected x-coordinate value is defined as the minimum x-coordinate. And the smaller one of the x-coordinate value of the plus side edge of the electrode pad and the x-coordinate value of the barycentric position of the new needle trace having the smallest x-coordinate value at the edge is the largest x-coordinate. The inspection method according to claim 1, wherein the y-coordinate range of the contactable area is obtained in the same manner as the x-coordinate value range. A computer is driven to electrically contact a plurality of electrode pads of the object to be inspected placed on the mounting table and a plurality of probes of the probe card disposed above the mounting table, The contact positions of the plurality of electrode pads and the plurality of probes are prepared in preparation for the inspection by using the traces of the plurality of probes formed on the plurality of electrode pads by performing an inspection of the electrical characteristics. A program recording medium recording a program for executing an inspection method including a correcting step,
When the contact positions of the plurality of electrode pads and the plurality of probes are corrected using the needle traces, the program drives the computer to claim 1. A program recording medium for executing the inspection method described above.

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